<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <!-- 开发环境版本，包含了用帮助的命令行警告 -->
  <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
    <div id="app" class="">
      <p>{{message}}</p>
      <input v-model="message"/>
    </div>
    <script>
    var vm = new Vue({
      el: '#app',
      data: {
        message: "Hello World!"
      }
    })
    </script>
</body>
</html>
